In combat sports such as boxing, martial arts such as taekwondo, dueling weapons such as fencing, and so forth, athletes compete in a duel. The object is to strike blows and score points while preventing an opponent from doing the same. A strike (also referred to as an “impact”) is characterized by applying force to a target with any part of the body (typically a hand, arm, foot or leg) or an inanimate object that represents a weapon. Typically, points are awarded in these competitions to athletes who successfully deliver a legal blow to designated targets. At the end of the competition, generally determined by the passage of a specific time frame, the athlete with the most points is declared the winner. Thus, training for such a combat sport requires feedback on the accuracy of a strike delivered to the designated targets, the force of the strike, the direction of the strike, and the reaction time. Athletes can improve their skill by receiving immediate and objective feedback of their performance.
Sports like martial arts, fitness and athletic training, and recreational activities have utilized targets and striking surfaces to provide focus and feedback. For example, foil fencing has long used electronic scoring that determines when a legal touch is made. In the Olympic Games of 2012, an impact measuring system was used to score TaeKwonDo competition successfully.
Related U.S. Pat. No. 7,891,231, which is incorporated herein in its entirety by this reference thereto, discloses installing an array of piezoelectric wires and magnetic field detection sensors in garments worn by an athlete to accurately evaluate and score strikes delivered in martial arts. For example, protective padding in a vest-like garment may contain sensors for detecting receipt of a strike. Boots and gloves may have embedded magnets that trigger sensors in the protective gear such as chest and head protection to detect delivery of a punch or kick. U.S. Pat. No. 7,891,231 discloses a multiple sensing algorithm to determine the efficiency of target impact. The algorithm relies on measurements from multiple different types of sensors. The force sensor, based on piezo film or piezo cable, indicates how hard the target was hit, and the magnetic proximity sensor indicates that the strike is in a appropriate target area.
The field of avionics has used IM sensors to measure aircraft motion to assist navigation. The detected motion involves roll, pitch and yaw. An IM sensor unit (IMU) typically consists of 3 axis accelerometers and 3 axis angular rate sensors to measure roll and pitch movement. In avionics, additional 3 axis magnetometers are used to measure yaw relative to earth magnetic field.
With the advent of advanced sensor technologies, new methods of impact evaluation are now possible.